1. Field of the Invention
This invention relates to a method and apparatus for reclaiming sand from foundry molds and the like whereby a finished product consisting of particles having a predetermined maximum size is obtained which may be then reused.
2. Description of the Prior Art
In the foundry industry, it has long been known to use sand molds for casting. Typically, the sand molds are a mixture of sand and resin (or sand otherwise chemically bonded) which is tailored to form a mold for a particular item to be cast. Once an item has been cast in a mold, the mold must be broken to remove it from around the item.
Rather than discard the broken molds, it has long been known in the foundry industry to recycle these molds to reclaim the sand. Once that is accomplished, the reclaimed sand may be used in further molds.
The devices developed to accomplish this has been of several types. Typically, they have utilized drums mounted for rotation. Some used grinding media such as metallic balls which would grind the material into finer particles upon rotation of the drum. Others used rib members within the drum to elevate the material as the drum rotated until the material reached the top portion of the drum whereupon the material, by action of gravity, would fall through the interior of the drum into the bottom portion of the drum. The impact of the fall helped break down the material.
The devices utilizing grinding balls work best on finer material rather than the larger chunks. The devices utilizing the rib members work best on the larger chunks due to their size. Consequently, many of the devices of the prior art utilized various combinations and configurations of each of these two types of devices.